call "CBL_THREAD_IDDATA_GET" using by reference iddata-ptr
                             by value           thread-id


  Using call prototype (see Key) Picture
iddata-ptr cblt-pointer usage pointer.
thread-id cblt-pointer usage pointer.

On Entry:

iddata-ptr Pointer tp the id-data area for the specified thread
thread-id Pointer to the thread identifier

On Exit:

return-code A value indicating success or otherwise. See RETURN-CODE Values For Thread-control Routines


Returns a pointer to the id-data area for the specified thread or NULL if no id-data area has been allocated to date.

thread-id might be NULL, in which case a pointer to the current thread's id-data area is returned.

If another thread's id-data area is retrieved by this function the user should make sure that any attempts to access it in all threads are protected by some form of locking (for example, by using CBL_THREAD_LOCK and CBL_THREAD_UNLOCK to frame all accesses to it).